#ifdef __APPLE__
#include <gl.h>
#include <glu.h>
#include <glut.h>
#else
#define GL_GLEXT_PROTOTYPES
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#endif
#include <stdio.h>
static char *TITLE = "test_materials_vbos";
static GLuint verticesId = 0;
static GLuint normalsId = 0;
static GLuint redId = 0;
static GLuint greenId = 0;
static GLfloat VERTICES[] = {0, 0, 0,
1, 0, 0,
1, 1, 0};
static GLfloat NORMALS[] = {0, 0, 1,
0, 0, 1,
0, 0, 1};
static GLfloat RED[] = {1, 0, 0, 1,
1, 0, 0, 1,
1, 0, 0, 1};
static GLfloat GREEN[] = {0, 1, 0, 1,
0, 1, 0, 1,
0, 1, 0, 1};
static void objects() {
/* vertices */
glGenBuffers(1, &verticesId);
glBindBuffer(GL_ARRAY_BUFFER, verticesId);
glBufferData(GL_ARRAY_BUFFER, sizeof(VERTICES), VERTICES, GL_STATIC_DRAW);
/* normals */
glGenBuffers(1, &normalsId);
glBindBuffer(GL_ARRAY_BUFFER, normalsId);
glBufferData(GL_ARRAY_BUFFER, sizeof(NORMALS), NORMALS, GL_STATIC_DRAW);
/* red */
glGenBuffers(1, &redId);
glBindBuffer(GL_ARRAY_BUFFER, redId);
glBufferData(GL_ARRAY_BUFFER, sizeof(RED), RED, GL_STATIC_DRAW);
/* red */
glGenBuffers(1, &greenId);
glBindBuffer(GL_ARRAY_BUFFER, greenId);
glBufferData(GL_ARRAY_BUFFER, sizeof(GREEN), GREEN, GL_STATIC_DRAW);
}
static void light() {
GLfloat LP[] = {0, 0, 10, 1};
GLfloat A[] = {0.1, 0.1, 0.1};
GLfloat S[] = {0.5, 0.5, 0.5};
GLfloat D[] = {0.5, 0.5, 0.5};
glEnable(GL_LIGHT0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glLightfv(GL_LIGHT0, GL_POSITION, LP);
glLightfv(GL_LIGHT0, GL_AMBIENT, A);
glLightfv(GL_LIGHT0, GL_SPECULAR, S);
glLightfv(GL_LIGHT0, GL_DIFFUSE, D);
}
void init() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_FRONT);
glEnable(GL_LIGHTING);
glShadeModel(GL_SMOOTH);
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT);
glClearColor(0.f, 0.f, 0.f, 1.f);
light();
objects();
}
void reshape(int width, int height) {
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(65.0, (float) width / (float) height, 1.0, 100);
}
void display() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0, 0, 5,
0, 0, 0,
0, 1, 0);
/* red triangle */
{
glPushMatrix();
glTranslated(-1, 0, 0);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, verticesId);
glVertexPointer(3, GL_FLOAT, 0, (void *) 0);
glBindBuffer(GL_ARRAY_BUFFER, normalsId);
glNormalPointer(GL_FLOAT, 0, (void *) 0);
glBindBuffer(GL_ARRAY_BUFFER, redId);
glColorPointer(4, GL_FLOAT, 0, (void *) 0);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
glPopMatrix();
}
/* green triangle */
{
glPushMatrix();
glTranslated(1, 0, 0);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, verticesId);
glVertexPointer(3, GL_FLOAT, 0, (void *) 0);
glBindBuffer(GL_ARRAY_BUFFER, normalsId);
glNormalPointer(GL_FLOAT, 0, (void *) 0);
glBindBuffer(GL_ARRAY_BUFFER, greenId);
glColorPointer(4, GL_FLOAT, 0, (void *) 0);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
glPopMatrix();
}
glutSwapBuffers();
}
int main(int argc, char **argv) {
int window = 0;
/* init glut */
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
glutInitWindowSize(640, 480);
glutInitWindowPosition(0, 0);
/* create window */
window = glutCreateWindow(TITLE);
/* set callbacks */
glutDisplayFunc(display);
glutReshapeFunc(reshape);
/* init gl, light and objects */
init();
printf("sizeof RED=%dn", sizeof(RED));
/* enter main loop */
glutMainLoop();
/* destroy window */
glutDestroyWindow(window);
return 0;
}
There should be one red triangle and another one in green.
I could not find the error yet.
EDIT: The example is now ok.
It is 24 bytes long (reported by sizeof) but should be 16 (four time float).
I do not know where the extra bytes are coming from, but I now know where to search.